Yarn supplying means for knitting machines



Nov. 18, 1969 A. E. COOKE YARN SUPPLYING MEANS FOR KNITTING MACHINES Filed Jan. 23, 1968 4 Sheets-Sheet 1 llb i/vvE/vT Re A LBERT Emwmm LDOKE rs im m, 25M {M Nov. 18, 1969 A. E COOKE 3,478,945

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YARN SUPPLYING MEANS FOR KNITTING MACHINES Filed Jan. 25, 1968 4 Sheets-Sheet 5 IA/VEVTOR:

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ATr m/avs United States Patent 3,478,945 YARN SUPPLYING MEANS FOR KNITTING MACHINES Albert Edward Cooke, Leicester, England, assignor to Newmark Instruments Limited, Croydon, Surrey, England Filed Jan. 23, 1968, Ser. No. 699,858 Claims priority, application Great Britain, Jan. 25, 1967, 3,717/ 67 Int. Cl. B6511 17/42, 17/20 US. Cl. 226-109 Claims ABSTRACT OF THE DISCLOSURE A yarn feeding means for effecting positive feed of yarn for supply to a point of consumption and having a pair of rollers between peripheral parts of which a yarn is fed, the rollers being drivable simultaneously in opposite directions by a common endless flexible driving element wrapping around driving portions or members formed on or coupled to the respective rollers and engaging opposite sides thereof along a wavy path, said driving portions or members being of less diameter than the yarn engaging periphery of the rollers and being urged towards one another by the tension of the flexible driving element.

The invention is for improvements in or relating to yarn supplying means for knitting machines and has for an object to provide a relatively simple and effective means for applying a positive feed to yarn on its way to a feeding point, irrespective of the number of knitting or loop forming stations involved. A further object is to provide means for the character indicated which can readily be applied to an existing machine.

In the production of knitted fabric of certain types it is important to ensure that the length of yarn incorporated in different parts of the fabric intended to be of equal size and shape is caused to be the same, in order to provide a fabric of good appearance and consistent quality. With the object of seeking to meet this requirement a system of knitting generally referred to as positive feed has been employed, this term being used to indicate that the length of yarn consumed on the needles is determined by a measuring device and not by the draw of the needles. The principles involved is widely accepted and various forms and methods for achieving the desired result are in existence, some being more efficient than others. The invention is concerned with improvements in what are generally known as pinch Wheel feeding units and their application on a knitting machine.

A pinch wheel knitting unit normally comprises a pair of wheels or rollers, one of which is driven at a determined speed by the machine the yarn being engaged between the peripheries of the wheels or rollers and fed at a rate determined by the speed and diameter of the driven roller. This arrangement is not particularly eflicient since the driven wheel or roller engages the yarn with only point contact or approximately so and the other wheel or roller which supports the yarn to cause its engagement with the driven roller is out of contact with the driven roller to its separation therefrom by the yarn and must be driven frictionally by the yarn imposing a drag on the latter and requiring the yarn to be pressed very firmly against the driven roller in order to receive its movement therefrom. Severe squeeze forces on the yarn are frequently necessary and these can have a distorting and damaging effect on yarns to be fed. A further disadvantage of the known arrangement of pinch wheels or rollers is its reluctance to permit knots to pass between the rollers due to the degree of pressure between them "ice needed to feed the yarn, with the result that when knots occur there is a likelihood of the yarn dragging and breaking and a fabric press-off occurring. When such pinch wheel or roller devices are applied to the various feeds of multi-feed machines difliculties are moreover encountered in driving the yarns satisfactorily and changing the speed of the wheels or rollers according to the stitch length required. The provisions of the invention seek largely or wholly to overcome these disadvantages.

In accordance with the invention there is provided a yarn feeding means comprising a pair of wheels or rollers between which a yarn is fed, said rollers being drivable simultaneously in opposite directions by a common endless driving band, chain or the like which wraps around driving portions or members formed on or coupled to the respective wheels or rollers at opposite sides thereof along an S- shaped path, the driving portions of the wheels or rollers or the driving members coupled to them being of less diameter than the yarn engaging peripheries of the wheels or rollers. By this provision the yarn is engaged by driven feeding surfaces on both sides so that a better engagement of the yarn is obtained and at the same time drag on the yarn by parts of the feeding device is avoided.

By the provisions of the invention a number of advantages are secured in the feeding of a yarn. The added degree of engagement with the yarn by driven moving surfaces reduces the amount of pressure needed to grip the yarn for its feeding movement so that the required positive feed can be secured with less tendency to damage the yarn, and by reducing the pressure between the two wheels or rollers knots in the yarn can be permitted to pass satisfactorily through the device without tendency to drag the yarn. Moreover by the manner of drive through the S-shaped path just referred to better control of the drive to the wheels or rollers is obtainable. The driving band, chain or the like for driving the wheels or rollers of the yarn feeding means may conveniently be driven from a master driving wheel or roller at an appropriate part of its path, by changing the diameter of which master wheel or roller the rate of yarn feed can be varied. The control of the drive to the wheel or rollers is unaffected by the number of feeding stations when the invention is applied to a multi-feed machine since at each feeding station adequate engagement with the wheels or rollers is secured by the 'S-shaped path of engagement by the common driving band, chain or the like.

Advantageously the wheels or rollers of a yarn feeding unit are mounted to permit relative movement between them towards and away from one another and are caused to be urged yieldably together to grip a yarn between them. This can be arranged by having one wheel or roller carried on a fixed mounting and the other on a movable mounting, for example, a pivoted arm, which is urged yieldably to move its wheel or roller towards the other one. Advantageously in practising the invention the movable wheel or roller is carried on an arm which is pivoted about such an axis that the drag or tension of the driving band, chain or the like urges the movable wheel or roller yieldably towards the other wheel or roller. By suitably choosing the position of the Pivot of the arm, feed movement can be applied to the yarn whilst permitting the movable roller to be readily deflected when a knot engages it so as to allow the knot to pass without breaking the yarn. By utilising the tension of the driving band, chain or the like to urge the movable wheel or roller towards the other wheel or roller the need for a spring or springs to assist in this purpose can be entirely avoided if desired. The pressure with which the wheels or rollers are urged together may be varied by adjustment of the tension in the driving band, chain or the like for example by movement of a jockey pulley or the like engaging it. In the case in which a number of devices are driven from a common driving band, chain or the like such tension adjustment will affect all of the devices simultaneously and to exactly the same degree.

In a convenient form the wheels or rollers have reduced parts formed between their ends to accommodate the driving band or chain and portions of full diameter on each side of such recessed parts.

The accompanying drawings show by way of example a convenient form of construction in accordance with the invention. In the drawings:

FIGURE 1 is a plan view with mounting parts omitted;

FIGURE 2 a front elevation view of a yarn feed unit for effecting positive feed at a knitting station of a circular knitting machine;

FIGURE 3 is a perspective view of a modified form of construction;

FIGURE 4 is a schematic elevation of a part of a circular knitting machine incorporating a feed unit as shown in FIGURE 3; and

FIGURE 5 is a schematic plan illustrating the driving of a number of feed units according to the invention around a circular knitting machine.

The drawings show two wheels or rollers and 11 which are driven in opposite directions to feed a yarn Y between them positively at a required rate. The roller 10 rotates on a fixed spindle 12 while roller 11 rotates on a spindle 13 which is supported between a pair of arms 14 which turn on a spindle 15 fixed to a supporting plate 16 to which the spindle 12 is also attached. The rollers 10 and 11 have yarn engaging cylindrical peripheries 10a and 1a and other spaced peripheries 10b and 11b of the same diameter between which and the peripheries 10a and 11a there are inwardly stepped cylindrical parts 100 and 11c. A driving band or tape 17 which is an endless band or tape serves to drive both of the rollers 10 and 11 in opposite directions by engagement with the reduced parts 100 and 11c, being wrapped partly round the roller 10 on one side and partly round the roller 11 on the opposite side in an S shaped path (or a mirror image thereof) as seen in FIGURE 1. The yarn Y is guided between the rollers 10 and 11 by yarn guide eyes 18 and 19, the guide 18 receiving the yarn from the direction from the yarn supply and guide 19 delivering it towards the point of consumption.

The arms 14 can turn independently of one another on spindle 15 so that the roller can automatically adjust itself to provide a required line of contact with roller 10 and/or with an intervening yarn or yarns. Thus the roll ers 10 and 11 may be used to feed between then either one or a plurality of yarns. In the latter case at least one yarn will be fed between the parts 10b and 11b of the rollers.

On a multi-feed circular knitting machine organised for positive feed of the yarns at each feed station there will generally be a yarn feeding device as shown in the drawings at each feeding station, but one such feeding device may be shared by two or more feeding stations, the devices being arranged in a circular row as seen in plan and operated by a common endless driving band or tape 17 which in addition to running partly round all the rollers 10 and 11 is guided to run at an appropriate point in its path round a master driving wheel as aforesaid.

The reduced parts 100 and 116 of the rollers 10 and 11 may be of smooth form as shown in which case the rollers are driven frictionally by surface contact with the tape or band 17. The reduced parts 100 and 110 may alternatively be provided with a circular row or rows of projections or teeth to receive a positive drive from a perforated tape or band or a chain the openings in which engage with the projections or teeth on'the rollers.

The position of the pivotal axis of the arms 14 is so chosen that the tension of the band or tape 17 or equivalent driving means serves to urge the roller 11 yieldably towards the roller 10 but to permit roller 11 to be readily deflected when encountered by a knot in the yarn so as to permit the knot to pass easily between the rollers 10 and 11.

In the modified form of construction in FIGURE 3, the positions of the fixed spindle 12 and roller 10 and the movable spindle 15 and roller 11 are reversed. The arrangements are otherwise the same and so the same reference numerals have been used to indicate corresponding parts. In addition to the inwardly stepped parts and for engagement of the drive band 17, the rollers 10 and 11 also have intermediate diameter cylindrical parts 10d and 11d to facilitate threading up the yarn to be fed between the peripheries 10b and 11b. The guider eyes 18 and 19 are carried on a bracket 20 which is movable up and down to move the eyes 18 and 19 above the parts 10a and 11a of the rollers for threading up purposes and non positive feed conditions, and down to the level of the mid portions of the parts 10a and 11a for positive feed of the yarn.

The construction is further modified as shown in FIG- URE 4 by the provision of extra yarn guide eyes shown in broken lines at 18b and 19b for use in guiding yarn fed between the peripheries 10b and 11b. The eye 19b is mounted in an extension 20a of the bracket 20 and the eye 18b is mounted in a downwardly extending opposite part 20b of the bracket 20. Thus when the bracket is raised guide eyes 18b and 19b are level with the separated step portions 10d and 11d of the rollers for threading up or non-positive feed of the yarn, and in the lowered position of the bracket 20 yarn passing through the guide eyes 18b and 19b is subjected to positive feed by the roller 'parts 10b and 11b. The part 20b of the bracket '20 depends to a lug 200 by means of which the bracket can be raised and lowered as and when required. Yarn Y is shown passing from a cheese 22 mounted on a bracket 24 and a post 26 of a circular knitting machine superstructure, through the guide eyes 19 and 18 of a construction according to the invention, through a yarn feeder 28 to dial and cylinder latch needles 30.

In FIGURE 4 the feeding unit of FIGURE 3 is shown mounted on a circular knitting machine. The bottom supporting plate 16 of the feeding unit has fixed (e.g. welded) to it an L- shaped bracket 31 the bottom limb of which is formed with an aperture 33 to receive a projecting lug of the plate 35 carrying a clamping screw 37. The bracket 31 fits on to a circular rail 29 extending around the machine and by inserting the plate 35 and tightening the screw 37 the supporting plate 16 is clamped in horizontal attitude in any desired position on the rail 29. The latter is supported at intervals by brackets 34 on depending rods 36 fixed to brackets 24 carried by posts 26 positioned at intervals around the machine and upstanding from a supporting base 39. The drive band 17 is shown as being driven by a master driving Wheel constituted by a flanged wheel 32 secured to an upstanding spindle 40 passing through a bearing bracket 41 mounted on the appropriate post 26 and also through the base 39. The spindle 40 is driven by means of a pinion or gear wheel 42 fixed to its lower end.

FIGURE 5 shows the arrangement of the drive band 17 around the driving portions of a number of rollers 10 and 11 in a multiplicity of circumferentially spaced feeding units mounted on the rail 29 of a multiple feed circular knitting machine at positions corresponding to the knitting stations. The band 17 passes around guide pulleys 38 to the driving wheel 32 the pulleys 38 being supported by brackets 43 from the rail 29. By means of the feeding units yarns are fed to the machine at the knitting stations at the same rate of positive feed.

What I claim is:

1. A yarn feeding means comprising in combination a pair of co-operating yarn feeding rollers having peripheral portions for engaging a yarn, means mounting said rollers for rotation to impart positive feed to a yarn fed between their peripheral portions, and means whereby said rollers may be driven simultaneously in opposite directions of rotation to feed the yarn, said means comprising rotatable parts co-axial with said rollers and in fixed relation thereto and of less diameter than the yarn engaging peripheries of the rollers and adapted to be driven by a common flexible endless driving element moving in a wavy path in turn against opposite sides of said rotatable parts.

2. Feeding means according to claim 1 having the yarn feeding rollers mounted to permit relative movement between them towards and away from another and yieldably urged together to grip a yarn between their yarn engaging peripheral portions.

3. A feeding means according to claim 1 having an arm arrangement carrying one of the said rollers and a pivotal mounting pivoting said arm arrangement about such an axis that the drag of the endless flexible driving element urges the roller carried by said arm arrangement yieldably towards the other rollers.

4. A feeding means according to claim 3 wherein the said arm arrangement comprises two arms at opposite ends of the movable roller independently pivoted about a common pivotal axis and having the movable roller provided with a spindle which is supported between said two arms.

5. A feeding means according to claim 1, comprising a flexible endless driving element for driving the rollers, a master driving wheel for driving the flexible driving element, mounting means for the master driving wheel, and means for rotating said driving wheel.

6. In a circular knitting machine the combination comprising a mounting, a yarn feeding means carried on said mounting, a driving spindle, a mounting for said spindle, a driving wheel mounted on said spindle for driving the feeding means, and a flexible endless driving element engaged with said wheel, said yarn feeding means comprising two opposed rollers having peripheral portions for engaging a yarn, means mounting said rollers for rotation in opposite directions to impart positive feed to a yarn fed between said peripheral portions, rotatable parts co-axial with said rollers and engaged on opposite sides by said flexible endless driving element, said rotatable parts being in fixed relation to the rollers and of less diameter than the yarn engaging peripheries thereof.

7. A combination according to claim 6 including a plurality of yarn feeding means each as specified in claim 6 spaced apart around the machine on said mounting and all having their yarn feeding rollers driven by engagement of their said rotatable parts which are co-axial with the rollers with a common flexible endless driving element.

8. A combination according to claim 6 wherein the endless flexible driving element is constituted by a belt and the said rotatable parts co-axial with the said rollers are driven pulley wise from said belt.

9. A combination according to claim 7 wherein the mounting means for the plurality of yarn feeding means is constituted by a rail extending around the machine and mounting means is provided to mount said roll in fixed position.

10. A combination according to claim 6 having yarn guiding means to guide a stretch of yarn between the yarn engaging peripheries of said rollers, said yarn guiding means being movable in a direction axially of the rollers to an inoperative and yarn threading position.

References Cited UNITED STATES PATENTS 3,243,091 3/1966 Rosen 226-188 3,361,317 1/1968 Levin 226188 ALLEN N. KNOWLES, Primary Examiner US. Cl. X.R. 

